Integration of electronic circuits has been developed along with reduction of the size and weight of electronic circuits. A power source voltage has been reduced along with miniaturization in LSI fabrication processes. Therefore, electronic circuits are relatively getting susceptible to noise. The immunity (noise resistance) of a device should be tested thoroughly, and various precautions should be taken prior to marketing of the device.
An electrostatic discharge test described in Non Patent Literature 1 (IEC61000-4-2 (the international standard of electrostatic discharge)) is generally known as an immunity test to an impulse.
Patent Literature 1 (Japanese Patent No. 3613269 (known patent of an immunity test)) discloses known technology of an immunity test.
Generally, most of waveforms applied to an electronic circuit are oscillating in the application methods of the related art. Therefore, a voltage actually applied to an electronic circuit cannot be defined. In many cases, an applied voltage is defined as a setting voltage of a voltage source at the time of application for convenience's sake. Specifically, even if a device could resist +4 kV with respect to a power source in an electrostatic test, for example, +4 kV was not actually applied to an electronic circuit in the device. Only a voltage about several times the power source voltage is applied, and a waveform oscillating in both of the positive direction and the negative direction with respect to the power source voltage is applied (FIG. 1).
In addition to the aforementioned device that charges a capacitor to apply the charge to an electronic circuit, a noise simulator as a device capable of generating a rectangular wave, an arbitrary waveform generator, and the like have been known as impulse sources. There has also been known a TLP (Transmission Line Pulse) generator used for testing a semiconductor protective element (see Patent Literature 2 (Japanese laid-open patent publication No. 2006-038542 (the example of a protective element test using a TLP generator))).